jan's worklog for singel stage cooler
Lets see if i this works out nicely. It's been a while since i've built a singlestage
I went to the garage and collected some parts to start with...
I'll make a simple single stage unit using the following parts:
-ACC GP16FB compressor (16cm³ displacement)
-decent condenser, no pics now as it arrives not until next week (pic will follow)
-some evap that i found in the garage. It fits into the vapo mount so i'll try if its ok.
-CPEV (never used one before :D)
-refrigerant: R402a
The unit will be mounted on a simple aluminium sheet. I've not planned a case for now.
All parts except the condenser:
http://www.coldbug.de/Bilder/sstage/parts.jpg
Today I prepared and brazed the evaporator. Its an simple stepper design so nothing special. I modified it to increase the surface area a bit.
And always remember, while using a bench drill you should wear your safety glasses. :D
http://www.coldbug.de/Bilder/sstage/jan.jpg
http://www.coldbug.de/Bilder/sstage/evap.jpg
The cooker helps warming it up. At least a bit.
http://www.coldbug.de/Bilder/sstage/evap1.jpg
Brazed and cooling down. Now i've to clean it and lap the bottom.
http://www.coldbug.de/Bilder/sstage/evap2.jpg
Today I got some work done. I assembled the suctionline and highside of the unit. Pics below:
First I lapped the evaporator. As my lathe is disassembled right now I did it manually :(
Start with rough paper and as you progress use finer paper until you get a flat evaporator bottom without grooves.
http://www.coldbug.de/Bilder/sstage/lapping.jpg
When I finished this I assembled the evaporator with the suction line.
http://www.coldbug.de/Bilder/sstage/suction1.jpg
Next I added the feed line for the CPEV
http://www.coldbug.de/Bilder/sstage/suction2.jpg
Now that the evaporator, suctionline and feedline were assembled I insulated it and put the evap into the Vapo mounting kit
http://www.coldbug.de/Bilder/sstage/suction3.jpg
This is the condenser I was waiting for:
http://www.coldbug.de/Bilder/sstage/condenser1.jpg
I did cut in M4 threads for easy fan mounting:
http://www.coldbug.de/Bilder/sstage/condenser2.jpg
With mounted fan it looks like this:
http://www.coldbug.de/Bilder/sstage/condenser3.jpg
http://www.coldbug.de/Bilder/sstage/condenser4.jpg
Now I mounted the compressor on the baseplate
http://www.coldbug.de/Bilder/sstage/mount1.jpg
next comes the condenser
http://www.coldbug.de/Bilder/sstage/mount2.jpg
http://www.coldbug.de/Bilder/sstage/mount3.jpg
Starting with the discharge line. I forgot a access valve, I'll add it later on when I finish the cooler.
http://www.coldbug.de/Bilder/sstage/hs1.jpg
http://www.coldbug.de/Bilder/sstage/hs2.jpg
http://www.coldbug.de/Bilder/sstage/hs3.jpg
Added CPEV and filterdryer
http://www.coldbug.de/Bilder/sstage/valve1.jpg
http://www.coldbug.de/Bilder/sstage/valve2.jpg
http://www.coldbug.de/Bilder/sstage/valve3.jpg
http://www.coldbug.de/Bilder/sstage/valve4.jpg
As I ran out of brazing rods the last thing I did was adding the suction line and some insulation:
http://www.coldbug.de/Bilder/sstage/suction4.jpg
http://www.coldbug.de/Bilder/sstage/suction5.jpg
http://www.coldbug.de/Bilder/sstage/suction6.jpg
Ok, here is the last part of my worklog.
I decided to use captube instead of cpev...
http://www.coldbug.de/Bilder/sstage/captube1.jpg
http://www.coldbug.de/Bilder/sstage/captube2.jpg
I did not have a t-connector to install a access valve in highside so i did one myself
http://www.coldbug.de/Bilder/sstage/t.jpg
http://www.coldbug.de/Bilder/sstage/t2.jpg
evacuating...
http://www.coldbug.de/Bilder/sstage/evac.jpg
...charging...
http://www.coldbug.de/Bilder/sstage/charge.jpg
...with r402a
http://www.coldbug.de/Bilder/sstage/r402a.jpg
Its some time ago I've built my last singlestage so i had to make a new load tester.
http://www.coldbug.de/Bilder/sstage/load1.jpg
http://www.coldbug.de/Bilder/sstage/load2.jpg
http://www.coldbug.de/Bilder/sstage/load3.jpg
255 watt :)
http://www.coldbug.de/Bilder/sstage/load4.jpg
Insulated evap mounted on loadtester
http://www.coldbug.de/Bilder/sstage/mounted.jpg
the insulated unit ready to test
http://www.coldbug.de/Bilder/sstage/unit.jpg
http://www.coldbug.de/Bilder/sstage/unit2.jpg
And this is the temp under load. Roomtemp was ~ 20 - 22°C
http://www.coldbug.de/Bilder/sstage/temp.jpg
The temp is not that good. I think the evaporator is not capable of this load. Also I've to change the captube as it is to restrictive. I won't have time for this until early january :( So this is is the cooler as it is for now...
But I'll change captube and evaporator to yield better performance as soon as I've the spare time for it.
Also I could not test the unit under a lower load as I don't have a variac right now.